Description

Cerci absent “cerci are either of a pair of simple or segmented appendages at the posterior end of various arthropods that usually act as sensory organs”

Outdoor species typically have two pairs of wings (males only) held roof-like over the body and called barklice.

Indoor species are usually wingless (or wings are reduced to small scales) and called booklice

Importance

There are about 2,200 species of psocids worldwide with about 270 species known from the North America. Although the psocids are sometimes called lice, none of them is parasitic. They are rarely damaging inside buildings; however, in large infestations:

They may cause significant damage to delicate materials such as books and furs.

In wall voids of new construction “mold growth before the plaster or sheetrock walls have dried out”

Biology

Psocids undergo simple metamorphosis

The females of some species of psocids can reproduce without fertilization

Each female deposits singly or small batches of sticky, oval, and covered with a silken web or debris eggs on food sources. Females lay in average from 20-50 eggs/lifetime. Eggs deposit average depends on the time of the year.

At 50-87 °F (Oct.- Jan.) , eggs deposit average 20

At 60-90 °F (June- Aug.), eggs deposit average more than 50

Eggs hatch in one-three weeks

Depending on optimal conditions (temperature, humidity and food availability), nymph will go through 3-8 molts in about two –eight weeks.

Adults will live normally from one to six months.

Management

Long-term management of psocids only can be achieved by reducing the moisture levels, sealing cracks and crevices where psocids may be entering or hiding, applying “first in, first out” food management policy, continuing inspecting and monitoring practices.

Non-Chemical Methods

Inspecting & Monitoring

Applying a regular visual inspection of susceptible materials using powerful flashlight and magnifying lens is necessary and recommended.

Inspecting for conditions favor to psocid infestations such as the presence of mold, fungi, high humidity or moisture is a good way to detect the infestations.

Sticky traps may not be attractive to psocids but they can be used in heavy infestations.

Physical Management Methods

Heat or cold treatments

Dry goods should be treated by placing them in a deep freeze for 24 hours (enclose the products in a plastic bag)

Heat treatments at 126°F for 8-10 hours can be used to manage psocids “egg is the most heat tolerant stage”

If applicable, infested materials can be exposed directly to a hot sun for one to two days

Reduce the relative humidity to below 45- 50%

Removal of pest life stages

Dry cleaning and vacuuming especially cracks and crevices

Discard infested materials outside the building

Prevention

Keep food storage areas cool, dry and well ventilated

Reduce relative humidity to below 45- 50%; a dehumidifier, fan or airing out a room help in reducing moisture

Eliminate condensation and repair any moisture problems

Store boxes, bags, books, and papers off the floor to minimize exposure to dampness

Check all new packets of food and place any vulnerable foods in sealed and washable containers

Use opened packets of food as soon as possible

Eliminating Harborage Sites

Seal all potential exterior entry points and all interior hiding areas in cracks and crevices in walls, between panels, where two units are jointed together and other similar locations